Tunnel-kiln



G, W. BOOTH.

TUNNEL KILN.

APPLICATxoN HLED MAY u. 1919.

Patented Mar. 9, 1920.

an Q

fnifvwmm air the goods `passing through the tunnel give up their heat. The air is still more intensely heated in passing over and around the portion of the tunnel forming the firing zone. This heated air passes over the tunnel in the pre-heating zone and. isled through the passages l1 to fines 4. The

' goods on the trucks passing through the prevthe pre-heating zone of the tunnel if goods are being dried and burnt which are not liable to discoloration by any flue gases which may leak into the air in the air space 3. If desired, more or lessl of the hot products of combustion maybe circulated over the pre-heating zone of the tunnel by suitably operating the dampers 9 and 10 and, if desired, a certain proportion of the products of combustion may be allowed to enter the tunnel through the damper-controlled openings 19 when the character of the goods being burned will permit of their contact with the products of combustion in the preheating and drying zone.

It is preferable to separate the preheating zone of the tunnel from the firing zone byl means of a door 16, which may be of any de sired construction and will usually be arranged in` the ordinary manner to open simultaneously with the opening of the door 17 at the inlet end of the tunnel and the door 18 at the outlet end of `the tunnel;

Under some conditions it may be desirable to force a circulation of air in the pre-heatingjzone of the kiln. I therefore provide a fan'20, the discharge pipe of which commulliicat'es with the interior of the tunnel at some point in the length of the pre-heating zone. This fan may be used to supplement' the draft of the stack to supply more or less dry air to take the place of the saturated air passing from the drying bricks. l

What I claim as my invention is z-f 1. A tunnel kiln having an air space formed in its walls extendinglongitudinally of the preheating, firing and cooling zones of the kiln; a furnace communicating with the interior of the firing zone of the tunnel adjacent the cooling zone; a stack adjacent the other end of the firing zone communicating with the interior of the tunnel; a vflue i' located adjacent' the lower part of the tunnel communicating at one en with the stack,

and at its' other end with'the air space afore said adj acent'fthe inlet end of the tunnel.

2. A tunnel kiln constructed substantially as set forth in claim 1 in which a plurality 0f damper controlled passages extend downI beside the tunnel from the air space to the lower flue at different points longitudinally:

of the preheatin zone of the kiln.

3. A tunnel ki n.constructed substantially as set forth in claim 1 in which the communlcation between the tunnel and the stack is damper controlled and a damper controlled communication is formed at substantially the same point between the tunnel and the.

air space.

4. A tunnel kiln constructed substantially as set forthl in claim 1 in which the'communication between the tunnel and-the stack is damper controlled and a damper con* trolled communication is formed at substantially the same point between the tunnel and the air space and also a series of damper controlled openings into the tunnel from the air space at different points longitudinally of the preheating zone of the kiln and a series of moist air exit openings into the lower flue from the tunnel at different points longitudinally of the tunnel.

5. A tunnel kiln constructed substantially as set forth in claim 1I in which a plurality of damper controlled passages extend down beside the tunnel from the air space to the lower flue at different points longitudinally of the preheating zone of the kiln, and also a series of damper controlled openings intol of the kiln and a series of moist air exit openings into the lower flue fromthe tunnel at different points longitudinally of the tunnel.

6. A tunnel kiln constructed substantially as set forth in claim 1 provided with a door whereby the may be cut o from the firing Zone.

7. A tunnel kiln having an air Vvspace formed in its walls extending longitudinally of the preheating, firing and cooling zone of re-heating zone of the kiln l the kiln; a furnace communicating with the A interior of the firing zone of the tunnel adjacent the cooling zone; 'a stack adjacent the other end of the firing Zone communicating with the interior ofthe tunnel; a Hue located adjacent the lower part of the tunnel,"open ings being provided leading into the tunnel from the air space and from the tunnel into the lower flue, said openings being located at different points longitudinally of the preheating zone of the furnace.

8. A tunnel kiln constructed substantially as set forth in claim 7 in which the communication between the tunnel and the stack is damper controlled and a damper controlled communication is formed at substantially the same point between the tunnell and the air space.-

9. A tunnel .kiln constructed substantiallyh as set forth in claim 1 in which the communication'between the tunnel and the stack is damper controlled andl a damper con- -zone of tho kiln and a serios of moist an* exit openings into the loweil flue from the tunnel at different points longitudinally of 'lie itunnel;

10. A tunnel kiln constructed substantially as set forth in claim l in which a plurality of damper controlled passages oziend down beside the tunnel from the air space to the lower Hue at different poins longitw dinlly pro-homing Zone' of the kiln, and also a .Sei s of oponings into the tunnel from *alle ail: ai; cli'lip'oren points longitudinally @E tlio pil-@limiting zone of the kiln noi a series of moisi; nii* exit openings inlqo the lowoi ilu@ from Elio tunnel at different points longitnclinnlly of tlio'tunnel. l

'loronuo Unit. aliis 2nd day of Signed nl Pmi'il Uli.)5 in lle pi'esonoe of 1he 'two undersignod winossos. 

